Hi Amra, yes the cabanas are a bit of a walk to the restrooms, but the area is not that huge. Personally, I can find enough shade that a cabana would not be worth the extra money. That is totally your call, however. A friend of mine wouldn't go ashore without one. I hope you enjoy the Ruby and Princess cruise lines. They are our favorite line, so far. The Ruby is beautiful.
Here is a link to some pictures of the Emerald, her sister, if you care to take a look. Please let us know how it went when you return. I'm excited for you on your first cruise! Just remember cruising is addictive. I get just as excited, if not more, each time we go. Have a wonderful time!